Remember, the maker of muzzleloaders typically had a big bore to work with and may not have been too worried about torsion. His steel/iron was also dead soft but good for lead bullets. Ouch! varies as the forth power... θ = 32 L T / (G π D^4)
Dunlap shows a drawing for the take up of the rifling cutter. I like the idea of rotating the barrel but some of the sine bar rifling machines used during WWII are still being used. Clearly craftsman using either broaching or cutters produce good barrels. Apparently the hammer forged barrels are still the best but the $ 1E+6 price tag limits ownership. ;-) But it is like one shooter said,"I shoot one round and I know where I hit. It is only subsequent rounds that confuse the issue". Dave On Fri, 2014-09-05 at 09:28 -0400, Gene Heskett wrote: > On Friday 05 September 2014 03:34:41 Gregg Eshelman did opine > And Gene did reply: > > On 9/5/2014 12:13 AM, Dave Caroline wrote: > > > Mount the cutter bar on a rotary for controlled rotation, then a > > > A plain g1A(rotation degrees)x(barrellength) would be what I would > > > do. > > > > > > I have done some very coarse helix cuts that way > > > > > > The taper wedge putting on the cut is interesting, that can be the > > > same/similar just adjusting the out stroke as it runs > > > > Longer stroke after each round of passes to bung the wedge in farther. > > Another method uses a threaded plug to push the wedge in to raise the > > cutter. > > > > That could be automated too by using a second rotary indexer with a > > hole into which the end of the plug fits. After each trip around all > > the grooves, run the tool farther out to engage the plug and turn it. > > Lock the indexer so it will remain aligned for the next adjustment. > > > > Either way simpler and on the fly adjustable VS the complicated > > ratcheting system that has to be rigged to only advance after the > > barrel is turned a full revolution. > > > > It might be possible to mount two or three or more cutters at once, > > combining the features (mainly speed) of button and broach with the > > fine accuracy of cut rifling. > > > > With three cutters a six groove barrel could be cut in only two passes > > between advancements of the cutters. > > That would stretch the ability to make a uniform cut. So it is not > something that I would attempt. As for putting an High Density rear shoe > on the back of the cutter carrier, I would fear for its ling term life > since it would be running in the cutters debris, ripping it up quickly. > > Here in WV we have an annual labor day bash out at Jacksons (Stonewall) > Mill, and one of the exhibitors is a black power rifle maker of > considerable years who has brought his rifling rig to the show on several > occasions. > > Hand powered, driving the cutter with a set of handles similar to an old > push mower, the rifling bit is turned by a spiral groove chiseled into a > log about 6" in diameter, groove worn dead smooth by decades of use. He > meticulously cleans the cutter and applies a drop or 2 of some sort of > cutting oil to it before every pull, and its designed to catch its own > shavings so the barrel stays fairly clean. His wedge is IIRC driven by a > screw that gets tightened 1/4 turn at a time. The rifles he brings to the > show are all Kentucky style flintlocks. But they are all tagged only as > to caliber & date he completed them. I saw him turn down an offer of > $5,000 for one of them several years ago. As Ky style flintlocks go they > are, every one of them, truly both a labor of love and a work of art. > Worth every bit of that $5000 offer. > > I asked about his stock wood and he said he has driven as much as 20,000 > miles over a 3 or 4 year period before buying the "right" plank. The > target he says that rifle shot laying on the table under each are equally > impressive. No flyers, often under an inch at 50 yards for 10 shots. > > > For the group's next trick, automate the deburring and lapping process > > while at least duplicating if not surpassing the accuracy of hand > > lapping. ;-) > > If the cutter is sharp & kept clean, de-burring is the first shot. It > really should not need anything more. > > Cheers, Gene Heskett ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
